1. Field of the Invention
The present invention relates to a disk writer and a writing method thereof, writing servo data on a disk forming a hard disk drive (HDD).
2. Description of the Related Art
Generally, a HDD is widely used as an auxiliary memory unit for a computer system. The HDD comprises a disk on which data is stored, and a head writing data on the disk and reading data stored on the disk.
The HDD writes data on and reads data from a predetermined track of the disk in response to reading and writing orders of the computer system.
To successively write and read data on and from the disk, there is needed servo data to control the head to move along target tracks of the disk. The servo data is written by a servo writer during a servo writing process when the HDD is manufactured.
There has been used a method of writing servo data on the disk, in which the servo data is written on each disk after one to three disks are assembled. However, as the HDD recently has been becoming high in density and large in capacity, this method takes much time and needs many servo writers, so that it is not suited to present requirements. Therefore, there is proposed a method in which the servo data is written on a plurality of disks mounted to a rotation axle such as a hub before the disks are assembled. This method improves the productivity compared with the former method since the servo data is written on the plurality of disks at the same time.
On the other hand, both of the conventional servo-writing methods are in need of the servo writer.
As shown in FIG. 1, a conventional servo writer 130 comprises a servo head 131 to write the servo data on a disk 110, a servo writer arm 135 supporting the servo head 131, and a positioner 137 rotatably supporting the servo writer arm 135 and adjusting a position of the servo head 131.
With this configuration, a worker controls the positioner 137 with a jig or his/her eyes so as to position the servo head 131 on a start track 113 of the disk 110, at which the servo writing process is started. Then, the servo head 131 starts writing the servo data on the disk 110 at the start track 113.
However, in the conventional servo writer 130, the position of the start track 113 is likely to vary whenever the servo writing process is performed since the start track 113 is determined by the jig or an operator's eye. Further, the position of the start track 113 is likely to vary because of assembling or processing errors generated when the servo head 131 and the servo writer arm 135 are replaced with a new one. If such disks 110 are assembled within the HDD, the start track 113 of the disk 110 may be out of a predetermined moving range in which a head (not shown) of the HDD moves to seek the start track 113, so that the head of the HDD cannot read the start track 113, thereby causing a reading error in the HDD.